Ichthyophthirius multifilis – more commonly referred to as Ich – is a widespread parasite in aquariums. It burrows into your fish and feeds on dead skin cells. Although it’s the equivalent of minor skin irritation in humans, it can cause infection, distress, discomfort, and even death for your freshwater fish. What’s worse is that the parasite multiplies rapidly, so most aquarists find that all fish in a tank become infected. If you see Ich, you will want to quickly decide on the best ich treatment option for your situation.
Thankfully, this aquatic parasite can be treated with various medications that are incredibly effective, provided they’re used properly. It is a very common fish disease.
Below, we’ll review everything you need to know about Ich, how to prevent and treat it, and the best medicines for eradicating the parasite in your aquarium.
Best Ich Treatment Options:
What is Ich?
Ich is the most prevalent parasite that infects aquariums. Most experts believe that the parasites are present in just about every fish tank, but healthy fish have a strong enough immunity to keep the parasite from becoming a health issue.
Ich can become a problem for your aquarium fish if their immune system becomes compromised for any reason. Most often, stress results in an inadequate immune response to disease and infection, so distressed fish are more susceptible to Ich.
Common stressors for fish include:
- Changes in water temperature
- Fluctuating water pH or hardness
- An inappropriate temperature or pH being sustained in the tank
- A high concentration of ammonia or nitrites due to improper cleaning
- Attacks from unfriendly tank mates
- Sustained or inappropriate lighting
- Lack of hiding spaces or coverage on the surface of the tank
- And many others.
Any of these changes to your tank can create distress in otherwise healthy fish and leave them open to attack from the Ich parasite. Almost all species of freshwater fish – goldfish, betta, tetras, etc. – are subject to ich infections.
What are Ich Symptoms?
The most common symptom of Ich is the development of small white spots on a fish’s skin. These are natural immune responses to the irritation caused by the parasite feeding.
When one of your fish first gets infected, you may not notice unless you keep a very close eye on your tank. A single white spot typically precedes additional infected areas. Once the parasite has fed successfully on an immunocompromised fish, it sinks to the bottom of your tank and replicates, often into hundreds or thousands of offspring. The offspring then continue to latch onto and feed on fish in your tank, leading to additional white spots on the skin of one or more fish.
The parasite’s feeding sites become inflamed and itchy, so your fish may notice your fish scraping against rocks or gravel to alleviate the discomfort. This kind of scratching is a good indication that they have become infected.
As Ich gets worse, your fish may become far less active than they typically are, and they may refuse to eat. Continuous skin irritation from the feeding parasites and scratching can cause abrasions on your fish’s skin, which is often a symptom of advanced Ich infections. One sick fish can also lead to ich outbreak in your tank.
How Do You Prevent Ich?
Ich can be stressful for you and your fish, and treatment is challenging due to how the parasite replicates and how widespread of an issue it can be in a single tank. Prevention is often easier than cure. Luckily, there are some things you can do to help prevent your tank from becoming infected.
Limit Fish Stress
One of the best and easiest things you can do to prevent Ich infections is to keep your fishes’ distress to a minimum. Stressed fish have lowered immune responses, so keeping them happy and healthy will naturally help them resist Ich infections.
Maintaining proper, constant aquarium water conditions, pH, and hardness is an excellent way to keep the immunity in your tank at a maximum. Overcrowding and lack of plant coverage or hiding places also stress most fish species. As such, limiting the number of fish in each tank and ensuring each has a dedicated area to hide can help prevent infection.
Be Selective with New Fish and Plants
Even the best-kept and well-maintained aquariums can get infected when outside sources bring Ich parasites in with them. One of the more common ways tanks get infected is when new fish or plants are introduced to an existing tank.
Many aquariums in pet stores and retailers are community tanks that are overcrowded and more likely to contain parasites and diseases. As such, it’s essential to be selective when it comes to purchasing fish or plants to add to your tank.
Always avoid buying fish that are kept in tanks with others that are visually infected. If you notice that a tank contains dead or sickly fish, we strongly recommend staying away from that retailer altogether or choosing from a different tank.
Purchasing fish from sources that don’t have them shipped multiple times or over long distances can help reduce the risk of bringing Ich into your tank. Shipping stresses fish and leaves them susceptible to Ich. We recommend buying from reputable and responsible sources that don’t subject their animals to excessive shipping and handling.
Plants ideally should not be kept in tanks with fish in them, and we recommend buying from plant-only tanks. If you do purchase a plant from an aquarium that also houses fish, quarantining is best practice.
Quarantine New Fish and Plants
Even if you follow all other purchasing guidelines, a seemingly healthy fish or a plant from a healthy tank could contain Ich parasites. As such, you should plan on keeping your new addition in a dedicated quarantine tank for about two weeks before introducing your fish or plant to your tank.
A quarantine tank can limit Ich to a single fish or plant and prevent it from spreading to your entire tank. Additionally, driving your fish home from a pet store can cause distress, so letting them mellow out in solitude can help bring their stress level down and reduce the chance of infection before introduction to your main aquarium.
Be Careful with Food Choices
Many aquarists choose to feed carnivorous fish live food, which often includes feeder fish. Since feeder fish are cheap and meant for food, they’re usually kept in community tanks and, unfortunately, don’t get the best care in pet stores. High-volume tanks with often less-than-ideal conditions lead to a high chance of feeder fish getting infected with Ich.
When you bring your feeders home to give to your fish, they can easily infect your tank. As such, it’s important to choose the healthiest feeder fish possible if you do prefer live food.
Frozen food and protein-packed flakes can be good alternatives and have less chance of infecting your fish, provided they are stored and handled correctly.
Quarantine Infected Fish
Lastly, quarantining infected fish won’t prevent an infection from starting, but it will help stop it from spreading to over tank inhabitants.
As soon as you see signs of infection on any of your fish, immediately move them to a conditioned quarantine tank for treatment. Keep your ich patients out of the main tank. Carefully inspect your other fish for signs of infection and remove them from your main tank if necessary.
Limiting the parasitic infection to one of two fish can make your treatment process significantly easier and faster.
How Do You Treat Ich? What Are the Different Types of Ich Treatment?
It is possible to treat Ich quickly and have it eradicated from your freshwater aquarium in a week or two. We’re going to detail the entire process from beginning to end below. These guidelines will help you isolate the infection and kill the parasites quickly before they do irreparable damage to your fish.
The first step you’ll want to take when you see symptoms of an Ich infection is to relocate the affected fish to a quarantine tank. A dedicated tank for treatment will help kill the parasite more quickly, and the changes you’ll make to the water conditions won’t put undue stress on your unaffected tank inhabitants or the balance of the biological media in your filter.
A quarantine tank isolates the infection for the most direct treatment, and you can customize the tank set up to provide the most comfortable home for your infected fish. This will help reduce stress to a minimum and aid in a speedy recovery.
Once your infected fish is quarantined, you’ll want to optimize the environment for killing off the parasite.
1. Raise the Water Temperature
First, raise the water temperature to around the upper limit that is healthy for your fish species. Higher temperatures speed up the life cycle of the Ich parasite and make the treatment process faster. The parasite will infect its host for a shorter amount of time before exiting and sinking to the aquarium floor to replicate.
The goal with Ich treatment is to provide medication when the parasite is not inside the host. While it’s feeding, Ich is protected by your fish’s scales and epithelial cells, so the treatment will only be effective upon host departure. Higher water temperatures will mean a short amount of time the parasite feeds on your fish, thereby exposing it to the medication faster.
2. Discontinue Carbon Filtration
Typically, activated carbon, resin cartridges, or other chemical filter media attract and absorb chemicals suspended in your tank water. This is helpful in healthy tanks where dangerous chemicals can build up.
However, chemical filtration can absorb the chemicals that are used to make up the Ich medication. Your Ich treatment will effectively be rendered useless in a carbon-filtered tank. Provided you carry out regular water tests in your quarantine tank, the typically harmful chemicals absorbed by the carbon can be kept at safe levels without too much effort.
3. Apply Medication
Once your water is heated to a level at which the Ich is exposed quickly and the carbon filtration has been discontinued, you can begin applying medicine to your water. The medication will take one to two weeks to kill off all of the tank’s parasites and will typically require a new application daily. Always follow the manufacturer’s dosing and scheduling recommendations.
Our top choice for Ich medication is the Seachem ParaGuard. It’s very affordable, has a high success rate, and can be used to treat Ich as well as most other parasites, bacteria, and fungal infections. Each bottle can treat around 500 gallons, so it’s sure to last through multiple aquarium problems.
Things to Consider Before Selecting an Ich Treatment
Not all Ich medications are created equal, so choosing the right one can be challenging. Make sure you pay close attention to the below factors when shopping for the best treatment option, as these can make a big difference in the efficacy of the medication and the ease of use.
The most significant difference you’ll see from medication to medication is the type of chemical in the solution. Several different chemicals can treat Ich effectively. However, they have varying levels of toxicity, and some are far safer for your fish and plants than others.
Before purchasing an Ich medication, you must check the label and instructions to confirm that it’s safe for your aquarium. Many of the more powerful medicines can be toxic to all fish in high concentrations. Still, even some generally safer products are unsuitable for use in aquariums that house plants, invertebrates, or scaleless fish.
You should confirm that a medication will be safe for all tank inhabitants before use. Failing to do so can quickly lead to additional complications and even the death of your fish, plants, snails, or other living creatures.
Additionally, some medications can kill or disrupt the beneficial bacteria living in your filter. These bacteria are responsible for maintaining healthy levels of ammonia, nitrites, and nitrates, so they’re crucial for overall tank health and the well-being of your fish. If you choose a medicine that may be detrimental to nitrobacter, ensure you only use it in a quarantine tank, or you’ll risk throwing off the balance of your primary aquarium.
Many commercially available Ich treatments are a combination of these primary chemicals. Some include other constituents that help protect your fish from bacteria and fungal infections simultaneously.
You should consider what infections a medication can treat, as more uses will allow you to use a single product to cure most common conditions. Having a container of Ich-only medicine is helpful for Ich outbreaks, but an all-in-one solution can save your fish from a variety of bacteria and fungi as well.
Price and Dosing
Lastly, you should consider the medication price and the number of doses included in each container.
Some options may appear more affordable than others, but if the dose is significantly larger, it will treat fewer Ich instances. Many medication containers are dosed according to treatable gallons, so do some simple math and figure out how many isolated infections you could cure with a single bottle. This will give you an idea of how long your medication will last.
8 Best Ich Treatment Options
This medication is our favorite because it is safe for use in tanks containing plants, healthy bacteria, invertebrates, and scaleless fish. As long as you follow the dosing directions carefully, you won’t have to worry about harming any of your tank inhabitants.
It’s safe for use in freshwater and saltwater environments, and it’s very useful in both, as long as you follow the directions.
It comes in a 500 mL bottle that can treat up to 1,000 gallons. You can treat parasites, bacteria, and fungi with this medication, so it’s genuinely a cure-all for common fish ailments.
- It features chemicals with a low toxicity
- The formula is safe for fish, plants, and invertebrates
- It is very effective against Ich
- It can be used to treat other common ailments as well
- One bottle can treat 1,000 gallons
- It takes a bit longer to treat than higher toxicity options
- It is relatively expensive
This medication treats Ich very effectively, and it can be used to treat other common diseases and parasites, including Velvet.
It’s safe for most fish, including those that are scaleless. However, it can be harmful to invertebrates and plants, so it’s strongly recommended only for quarantine tanks.
It comes in a relatively affordable bottle that can treat up to 1,000 gallons, so you get good value for the money.
This product can add a light blue hue to silicone, so expect some minor discoloration around adhered decorations and tank seals.
- The formula is aldehyde based, making it safe for fish
- The chemical make-up is effective against Ich despite being low-toxicity
- It’s very effective for treating Ich
- You can use this to treat other common infections from bacteria and fungi
- It’s safe for most fish, including those that are scaleless
- It tends to discolor silicone
- It can be harmful to invertebrates and plants
This isn’t safe for use around invertebrates, plants, live rock, scaleless fish, or particularly sensitive fish species. As such, we strongly recommend only using this on hardy fish in a quarantine tank.
It’s only effective against Ich and other parasites, so you can’t use it for bacterial or fungal infections. However, it works very rapidly and can bring about signs of improvement in just a few days.
It’s very inexpensive and comes in a small bottle that can treat up to 400 gallons. The applicator tip makes it a breeze to use.
- It includes an applicator tip to make dosing very straightforward
- The formula works rapidly in as little as two days
- It’s effective for the treatment of Ich and other parasites
- It’s very inexpensive
- It’s not safe for invertebrates or scaleless fish
- It can kill live rocks and plants
This medication is only effective against Ich and other protozoa, so you’ll need additional products for dealing with bacterial or fungal infections. It does have a high success rate for curing Ich.
It can stain water and silicone blue, so we recommend only using this in temporary quarantine tanks or primary aquariums with blue seals.
It aids in slime coat protection to help keep your fish healthy after the Ich is eradicated.
This comes in small, affordable bottles, but each can only treat around 120 gallons. It may end up costing you more than other options in the long run.
- The formula aids in slime coat production
- The small bottle it comes in is easy to store
- It treats Ich quickly and effectively
- It’s very affordable
- It’s not safe for sensitive fish, plants, or invertebrates
- It may discolor silicone blue
This medication comes in tablet form, making it far more challenging to get precise doses than with liquid medicines. However, they are far easier to store, and they require less work from you, as they are slow-release tabs.
It can be used to cure Ich, bacteria, and fungal infections, so this medicine is useful in various situations.
This has a higher toxicity than many other products, so it isn’t safe for scaleless fish, invertebrates, or plants. As such, it should only be used in a quarantine tank.
It’s relatively expensive for the number of doses you get.
- Tablet form makes application very easy
- The solid doses are very easy to store long-term
- It treats Ich with a high success rate
- It can treat bacteria, fungi, and other parasites as well
- It’s challenging to get a precise dose
- It isn’t safe for invertebrates or scaleless fish
- It may kill plants and living rock
This Ich medicine consists mainly of cupramine copper, which is very strong and can rapidly wipe out an Ich infection. It won’t treat bacterial or fungal infections.
It’s not safe for invertebrates, scaleless fish, and some plants, but most hardy fish won’t be affected much by the medicine if it’s appropriately dosed. The toxic dose is relatively low, so you’ll need to be very careful when applying it.
This medication is moderately priced, but each bottle only treats just over 500 gallons. As such, it may be more expensive than other options over time.
- The formula works quickly to eradicate Ich
- It can be filtered out entirely with activated carbon once treatment is complete
- It’s very effective at curing Ich
- The dropper makes application a breeze
- It won’t cure bacterial or fungal infections
- It’s more costly than other products over time
- It isn’t safe for scaleless fish, invertebrates, or plants
This medicine is formulated to be safe for most aquatic organisms, including scaleless fish, invertebrates, and plants. The low toxicity makes it easy to use in most tanks.
However, this product’s safety also makes it less effective against Ich, so it may take a longer time to treat effectively than many other products.
This comes in large bottles that are reasonably affordable. However, a single dose is very large, so one bottle will only treat around 25 gallons. This will end up costing you more than most other products in the long run.
- The formula makes it safe for just about any aquatic organism
- The large dose makes using it easy and precise
- It is safe for scaleless fish, plants, and invertebrates
- It won’t disrupt the beneficial bacteria in your filter
- It generally takes longer than other medications to cure an infection
- It is only suitable for treating Ich
- It is costly on a per-dose basis
This medication is all-natural and chemical-free, so you won’t have to worry about it negatively affecting your tank’s inhabitants. It’s safe for fish, scaleless fish, plants, reefs, and invertebrates.
It does take significantly longer to work than other options because it’s natural and has low toxicity.
This medicine can only be used to treat protozoa, so you’ll need additional products if you run into problems with fungal or bacterial infections in your tank.
It is very affordable and comes in a bottle that can treat up to 1,000 gallons, so it will likely last quite a while.
- It has a chemical-free formula
- It contains only natural ingredients
- It’s safe for fish, scaleless fish, plants, and invertebrates
- It’s very affordable
- It takes longer to work than other options
- It can only be used to treat parasites and other protozoa
Benefits of Using Ich Treatment
Ich is a pervasive parasite that can quickly infect your entire tank. It’s stressful and potentially painful for your fish, but it can be stressful for you as well if you aren’t equipped to treat it quickly. Below are the primary benefits of using Ich medication to treat the parasite.
1. It Works Quickly
There are some natural alternatives to Ich medication, including raising the water temperature, adding some non-iodized salt to your freshwater tank, and bumping up the oxygen content in your water. These methods are sometimes useful, but they can take weeks and even months to clear the infections of freshwater aquarium fish.
Many Ich medications are safe for fish but are toxic enough to kill the protozoa in your tank. They can often clear your tank of parasites within a week or two, and many begin working in as little as a few days.
2. It Makes Your Fish More Comfortable
Remember that, while curing Ich may be stressful for you, it’s even more so for your fish. The faster you solve the parasite problem, the sooner they’ll get relief from their discomfort and potential pain.
Ich parasites burrow into your fish’s skin and feed on dead epithelial cells. The infection site becomes inflamed and can be very itchy. You’ll often see infected fish scratch against rocks, gravel, or decorations in your tank in an attempt to satisfy the itch. This scratching can lead to open wounds on their skin, which are painful and also leave them open to other infections.
Ich medication can bring relief to your tank inhabitants quickly. Many products begin to work within a day or two and can give your fish some relief.
3. It Can Cure Other Diseases
Some Ich medications are formulated only for parasites, but others can be used to kill off bacterial and fungal infections as well.
Unfortunately, you’re bound to run into different infections as an aquarist, and being equipped to handle whatever you experience in your tank will help keep your fish happy and comfortable. Having an Ich medication on hand that can also cure other infections and diseases helps maintain healthy tank water at all times.
4. It’s Easy to Use, and It Works
Most Ich treatments come with exact instructions that detail how much to use for a given water volume at a given temperature. This information allows you to treat your tank in an effective way that won’t cause harm to your tank’s inhabitants.
Best of all, Ich medication works. It’s straightforward to get a precise treatment in place for your tank, and most products will kill off all of the parasites in your infected tank within a few weeks. They can give you and your fish some much-needed peace of mind.
Ich Treatment FAQs
Is Ich Always Present in Aquariums?
Many experts believe that Ich parasites live in all aquariums and only have a chance at infection when a potential host becomes stressed or has a lowered immune response for some reason. This would explain some random outbreaks that have occurred in many tanks.
Others believe that Ich parasites don’t persist in tanks without readily available hosts. They believe that the parasites are transported to the tank on new fish or plants introduced that have carried them from their previous tank.
There’s no doubt that Ich parasites can get into your tank when you transfer in a new animal or plant, especially if they were previously kept in a tank with sickly or dead fish where you purchased them.
However, the real answer to the question is unknown and hotly debated by aquarists. The best course of action for you is to assume that Ich parasites are always present in your tank and to keep your fish happy, healthy, and stress-free to prevent an infection.
Can Ich Cure Itself?
Some aquarists have experienced signs of Ich just going away with time and regular water changes. Unfortunately, Ich can appear to have gone away on its own, but it won’t be eradicated without intervention on your part.
Ich is an opportunistic parasite, meaning it will attack your fish and present itself on those that are stressed or have a lowered immune response. Healthy fish can get infected as well, but the infection is often not severe and may not result in visible white spots.
As such, reducing all stressors in an infected tank with Ich may appear to kill off the parasites. Instead, what is likely happening is that your fish are becoming less stressed, so they don’t present the apparent signs of the Ich infection. However, the parasite is still present, and any future stressors can quickly lead to visible proof of continuing infection.
Ich won’t go away on its own, and even if the white spots on your fish’s skin have disappeared without a cure being implemented, chances are the parasite is still in your tank and will come back at the first sign of weakness in your fish.
Can Fish Recover From White Spots (Ich)?
Fish can recover from Ich, and you can cure the white spots that appear on their skin. These spots are cysts that form over the feeding sites of the Ich parasites. They’re similar to blisters or scabs on human skin, and they serve to protect the area from additional damage. The spots will go away with proper treatment.
Can Humans Get Ich Disease?
Humans can transport Ich parasites from tank to tank. However, they cannot be infected by them.
Will Healthy Fish Get Ich?
Healthy fish generally don’t present symptoms of Ich, but they can be infected. Only stressed or otherwise sickly fish show signs of infection. Healthy fish have a proper immune response that will ward off the parasite.
How Do Fish Catch Ich?
Whether the parasite exists in your tank already or is introduced with the addition of a new fish or plant, it can move through the water and attach itself to any fish in your aquarium. Only stressed or sick fish appear to get infected.
How Long Does It Take for Ich Treatment to Work?
The timeline from treatment to eradication of Ich parasites in your tank varies with the medicine you choose. The fastest medications begin to work in just 2-3 days. Most take around 1-2 weeks for the treatment to be complete. Less toxic, more natural medications typically take more than a month.
Is Ich Treatment Safe for Snails?
Many Ich medications are unsafe for snails and other invertebrates. However, some low-toxicity products, such as the Seachem ParaGuard, are perfectly safe for snails.
Is Ich Treatment Safe for Fry?
Fry are typically more susceptible to chemical additives than adult fish, so a low-toxicity medication is best. Generally speaking, if a medication is safe for invertebrates, it likely won’t harm your fry.
Will Ich Treatment Kill Shrimp?
Some of the more toxic – and more effective – Ich medications will kill shrimp. If you have shrimp or other crustaceans in your tank, choose a medicine that is specifically labeled as being safe for invertebrates. A good, effective option is the Seachem ParaGuard.
Can You Overdose Ich Treatment?
Any additive to your tank water can be deadly or hazardous in high concentrations, including Ich medications. Always follow the directions on the bottle of medication you purchase to avoid issues.
If you accidentally add too much medication to your tank, reintroduce activated carbon back into your filter, as this will scrub out the chemicals suspended in your water.
Are Certain Fish Species More Likely to Get Ich?
Any fish species can get infected with Ich parasites. There is no research suggesting that one species is more susceptible to Ich than others.
What Ich Treatment is best for your tank?
Ich is a pervasive parasite that can infect any fish species. Sick or stressed fish are more prone to infection, so avoiding stress by keeping water and lighting parameters constant and appropriate is one of the best ways to prevent it altogether.
If you do notice Ich symptoms in your tank, quarantine the infected fish, raise the water temperature within the species’ limit, and use an Ich medication with regular water changes for the best results and quick relief. We recommend using Seachem ParaGuard, as it works quickly and effectively, and it’s safe for scaled fish, scaleless fish, invertebrates, and plants.